Why does my a / C switch from Defrost to vent mode?
Why does my a / C switch from Defrost to vent mode? The A/C system switches from vent to defrost mode under engine load (going uphill or overtaking another car). It is caused by a vacuum leak and as far as I've seen most of us had the same problem a loose red hose, here are some pictures of where to start looking first. Why is cold air directed to defrost? After driving 60 to 90 miles the problems recurs. The cold air is directed to defrost when engine accelerates, outside tempreature is high or there is upslope. Reservoir and...